science ghsgt review
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Science GHSGT Review. Biology. What is Biology?. The study of living things What is considered living? anything that has the ability to nourish, grow, and reproduce cells must be present. Cell Theory. The cell is considered the basic unit of life. - PowerPoint PPT PresentationTRANSCRIPT
Science GHSGT ReviewBiology
What is Biology?• The study of living things• What is considered living?
•anything that has the ability to nourish, grow, and reproduce
•cells must be present
Cell Theory• The cell is considered the basic unit of life.
• All living things contain at least one cell.
• Cells come from pre-existing cells.
Plant Cell versus Animal CellPlant Cell Animal Cell
Plant Cell versus Animal CellPlant Cell
• oblong/square-like shape
• cell wall (provides structure)
• chloroplast (location of photosynthesis/ energy production)
Animal Cell• round/circular shape• centrioles (responsible
for cell reproduction)
Cell OrganellesSTRUCTURE FUNCTION
nucleus control of all cell activities; location of DNA
mitochondria energy production
Golgi complex (apparatus)
assembles, sorts, and transports cell products
ribosome protein synthesis
chromosome composed of DNA containing genetic material
Cell Organelles (continued)STRUCTURE FUNCTION
cell membrane
phospholipid bilayer; maintains homeostasis; protects the cell
lysosome digests old cells and food (cleans up the cell)
endoplasmic reticulum
produces, stores, and transports protein (rough) and lipids (smooth)
flagella/cilia movement of materials
Prokaryotes versus Eukaryotes
Prokaryotes• “Pro-No”• No true nucleus• No membrane-bound
organelles• No well-organized
membrane• All prokaryotes are
bacteria (Monera)
Eukaryotes• “Eu-True”• True nucleus• Well organized
membrane• Membrane – bound
organelles• Most plants and
animals and other specialized organisms
Active versus Passive Transport
Active Transport• requires energy (low
concentration to high)• endocytosis and
exocytosis• active transport (ATP
is used)
Passive Transport• diffusion (particles
from high concentration to low)
• osmosis (water from high concentration to low)
• facilitated transport (diffusion using a membrane protein)
Organic CompoundsORGANIC
COMPOUND DEFINITION FUNCTION
carbohydrates sugars and starches provide energy
lipids fats (insoluble in water) store energy
proteins amino acidsresponsible for
most cell functions
nucleic acids DNA and RNA store hereditary information
Cell Membrane and Homeostasis• Homeostasis = The maintenance of a constant,
stable environment internally (ex: body temperature)
• Cell membrane utilizes active and passive transport• diffusion and osmosis depends on environment
(hydrophobic or hydrophilic)
Hydrophilic versus Hydrophobic
Hydrophilic• “water-loving”• inside of cell
Hydrophobic• “water-fearing”• outside of cell
Hypertonic versus HypotonicHypOtonic
• Higher concentration of water outside the cell
• Cell swells when placed in hypotonic solution
Hypertonic• Higher concentration
of water inside cell• Cell shrinks when
placed in hypertonic solution
Isotonic• Equal concentrations of
water inside and outside of cell
Genetics• The study of the inheritance of traits and how
genes pass on these traits from parents to offspring
• Mendel is the Father of Genetics (studied pea plants)
Important Genetics Vocabulary• trait: a characteristic of an organism that is
inherited (examples: eye color, hair type, etc.) • gene: basic unit of heredity made of DNA that
determines the characteristics of a trait• allele: the two different versions of a gene for a
particular trait (one received from each parent)
Genotype versus PhenotypeGenotype
• an organism’s genetic makeup
• includes the two alleles
• represented with two letters (example: Bb)
Phenotype• the physical
appearance of a trait• expressed by the
organisms genes• represented by
description (example: brown eyes)
Dominant versus RecessiveDominant
• an allele that expresses itself while hiding the effects of another allele
• represented with a capital letter
• example: Bb (dominant brown eyes dominates over recessive blue)
Recessive• An allele whose effects
are hidden by a dominant allele
• Represented with a lower-case letter
• example: Bb (dominant brown eyes dominates over recessive blue)
Probability and Punnett Squares• Probability is the likelihood an event will occur• Geneticists use Punnett squares to predict the
probability of genetic combinations• Example: When two heterozygous brown eyes
mate . . . B b
B BB Bb
b Bb bb
Theory of Inheritance• Chromosomes are the physical basis of
inheritance (carry DNA).• Variability results from dominant and recessive
alleles.• The chromosomes in the male gamete and female
gamete join together during fertilization to form a zygote.
• gamete = sex cell• zygote = fertilized egg
DNA• deoxyribonucleic acid• found in chromosomes in the nucleus• determines the hereditary traits of an organism• contains all the information needed for the
production of proteins• protein sequences determine traits
RNA• ribose nucleic acid• aids in protein synthesis in the ribosome• 3 types:
• messenger RNA: mRNA carries the DNA nucleotide sequence for a protein from the nucleus to the ribosome
• transfer RNA: tRNA transports amino acids (building blocks of proteins) to the ribosome
• ribosomal RNA: rRNA makes up the structure of the ribosome
DNA Replication• self-duplication of the genetic material• results in two new DNA molecules• occurs during interphase (just before cell divides)• proteins unwind the DNA helix and each strand
acts as a template for a new strand• unbound nucleotides attach . . .
• A-T (adenine binds with thymine)• C-G (cytosine binds with guanine)
DNA Transcription• to “transcribe” is to copy• mRNA is synthesized in the cell nucleus from the
DNA molecule• Just as in replication, the helix unwinds and free
nucleotides attach to make mRNA. . . • C-G (cytosine binds with guanine)• U-A (uracil binds with adenine)• Only DNA has thymine
• mRNA separates and moves out of the nucleus• DNA double helix reforms
DNA Translation• process of translating the genetic code to the
amino acid sequence• tRNA decodes the mRNA to read the DNA in order
to make the correct protein
Mutations• A mutation is any change in the DNA sequence.• A change in one nucleotide may cause a change
in the structure of the protein.• During pregnancy, observing a karyotype (a
chromosome picture) can detect chromosomal defects.
Taxonomy• The study of the classification of organisms
Classification• Kingdom• Phylum• Class• Order• Family• Genus• Species
• King• Phillip• Cried • Out • For• Good• Soup
Binomial Nomenclature• Classification system used to give all organisms a
two-part name• First name = Genus name• Second name = Species name• Example:
• scientific name of a wolf is Canis lupus
Kingdom Monera• bacteria• need water, nutrients, and a moderate
temperature to survive• autotrophs (make their own food) and
heterotrophs (obtain food from outside source)• decomposers (AKA saprophytes) = break down
dead organisms to release carbon and nitrogen• reproduce asexually (binary fission)• some possess flagella used for motion
Kingdom Protista• algae, seaweed, protozoans, water (slime) molds• found in aquatic or damp environments• organisms that don’t fit in any other kingdom• autotrophs (algae) and heterotrophs (protozoans)• reproduce either asexually or sexually• some have flagella or cilia for motion• gave rise to all other eukaryotic organisms
Kingdom Fungi• mushrooms, yeast, molds, mildews, rusts• all are heterotrophs (do not contain chlorophyll)• absorb food from environment• many are saprophytes (decomposers) that obtain
nutrients from dead or decaying plants and animals
• reproduce either asexually or sexually
Kingdom Plantae• autotrophs (utilize photosynthesis)• Two groups:
• bryophytes (nonvascular) have no roots, stems, or leaves and transport nutrients using diffusion (examples: mosses, liverworts, hornworts)
• tracheophytes (vascular) have roots, stems, and leaves that transport water and nutrients throughout the plant (examples: ferns, gymnosperms, and angiosperms)
• all reproduce both sexually and asexually (alternation of generations)
Kingdom Animalia• worms, insects, sponges, birds, mammals• all are heterotrophs that have a digestive cavity in
which food is digested and absorbed• all reproduce sexually, but some (like jellyfish) can
also reproduce asexually
Unicellular versus Multicellular
Unicellular• single-celled• composed of one cell• all bacteria and
protists• non-specialized cells
Multicellular• multi-celled• composed of many
cells• all other organisms
(fungi, plants, & animals)
• cells are specialized to perform different functions
Asexual versus Sexual Reproduction
Asexual• involves only one parent• no specialized sex cells
are produced• does not undergo meiosis• chromosomes are
duplicated in mitosis• Examples:
• binary fission = cell simply splits
• budding = offspring grows out of the side of the parent
• involves two parents so genetic diversity is increased
• specialized male and female sex cells (gametes) are produced
• gametes fuse during fertilization to produce a zygote (fertilized egg)
• gametes are formed in meiosis
• chromosomes are duplicated in mitosis
Haploid versus DiploidHaploid
• sex cells• contain one of each
chromosome• human haploid cells
have 23 chromosomes
Diploid• all non-sex cells• contain 2 copies of
each chromosome• human diploid number
is 46 (two sets of 23 – a set from each parent)
Mitosis• begins after interphase = cell growth,
chromosome (DNA)replication, and prep for division (most of a cell’s life cycle is spent in interphase)
• results in two identical daughter cells containing same number of chromosomes and genetic information as the parent cell
Phases of Mitosis1. Prophase = chromosomes become visible
(present), nucleus membrane disappears, and in animal cells, centrioles move to opposite sides of the cell
2. Metaphase = chromosomes line up in the middle of the cell
3. Anaphase = chromosomes move toward opposite poles of the cell (move away)
4. Telophase = chromosome become less distinct and nucleus membrane reappears; nucleus divides into two (cytokinesis)
Cytokinesis• occurs after telophase• cytoplasm divides forming two separate cells
Phases of Mitosis
Meiosis• cell division that results in the formation of
haploid gamete cells (sex cells)• Meiosis I
• reduction division• diploid cell divides creating two haploid cells
• Meiosis II• two haploid cells from meiosis I divide resulting in 4 haploid daughter cells
Mitosis versus MeiosisMitosis
• resulting cells have same number and kind of chromosomes as parent cell
• used for cell growth, tissue repair, and asexual reproduction
Meiosis• resulting cells have
half the number of chromosomes as parent cell
• used for gamete formation
Ecology• The study of interactions among organisms and
between organisms and their environment
Biomes• Biome = a large area characterized by a certain
climate and types of plants and animals• 6 major biomes on Earth
Biome CharacteristicsName CharacteristicsTundra permanently frozen subsoil
Taigalong severe winters;
summers with thawing subsoil
Temperate Forest moderate precipitation; cold winters; warm summers
Tropical Forest heavy rainfall; constant warmth
Grassland variability in rainfall and temperature; strong winds
Desert sparse rainfall; extreme daily temperature fluctuations
Biomes of the Earth
Ecosystem Vocabulary• Ecosystem = a part of the environment with its
organisms, their interactions, and the physical and chemical factors that affect them
• Community = populations of different species that interact in an ecosystem
• Population = all the individuals of the same species living in a community
Members of an Ecosystem• Producers = organisms that can make their own
food; autotrophs; examples: bacteria, protists, plants
• Consumers = organisms that eat other organisms to get energy; heterotrophs; examples: fungi and animals
Consumer Classification• Herbivore = primary consumer who only eats
plants; example: cow• Carnivore = secondary consumer who only eats
other animals; examples: shark and tiger• Omnivore = consumer that eats both plants and
animals; example: most humans• Scavengers = animals that find dead plants or
animals and eat them; examples: flies, wasps, cockroaches, earthworms
• Decomposers = break down dead organisms to receive energy; examples: fungi and bacteria
Predator versus Prey• All animals must eat to survive. Animals can be
either predators or prey.• Predators hunt prey.• With predators always on the lookout for a meal,
prey must constantly avoid being eaten. • Any adaptation the prey uses adds to the chances
of survival for the species.• Some adaptations are defense mechanisms which
can give the prey an advantage against enemies.
Survival Defense Mechanisms• speed
• You can’t eat what you can’t catch!• physical or chemical features
• physical examples: quills on a porcupine or hard shell of a turtle
• chemical examples: stink of a skunk; poisons of a dart frog
• camouflage • allows the animal to blend in with its environment to avoid
being detected• used by both predators and prey
Parasite versus Host• A parasite is an animal or plant that lives in or on
a host (another animal or plant)• Parasites obtain nourishment from the host
without benefiting or killing the host• Examples: canine heartworms, malaria,
hookworms, pinworms, tapeworm
Food Chain• a diagram that
shows the way energy is transferred from one organism to another
• each step in a food chain is called a trophic level
• begins with producers and ends with decomposers
Food Web• complex,
interconnecting food chains in a community
• more accurate than food chain
Pyramids of Biomass/Energy